Does my best friend have a crush on me?

I'm 13, my friend is almost 14. I was at her house the other day, and she pounced on me. She's a really aggressive person in general (especially with me) but it caught me by surprise and I fell over. She then proceeded to pin me down by draping herself over me. I told her I couldn't breathe. She then screamed at the top of her lungs and the sound reverberated around the room. Then she said "S." I said "uhhh, this is awkward" and tried to get up again, but she just pinned me down harder. Then I started to get mad and scared, but she said ESTROGEN and let me go. I told her that wasn't OK, but she just laughed it off. Does she like me, or is she just kidding? What should I do?